1. Field of the Invention
This invention relates generally to an improved dispenser closure for collapsible tubes and like containers.
2. Description of the Prior Art
As is well known in the art various problems and difficulties are encountered in providing suitable means for dispensing contents from tubes and like containers, particularly where the contents are in a paste or semi-liquid form.
Many types of dispenser-closure devices are in use, but these devices have features that very often restrict their use, and they are complicated to operate and expensive to manufacture.
As examples of various dispensing devices, the following United States patents are noted in the existing known art:
U.S. Pat. No. 3,876,118 to Adolfo A. Laredo comprises a rotary valve that rotates automatically when pressure increases in the dispenser, whereby the valve remains closed as long as the container is not in use.
U.S. Pat. No. 3,726,436 to Richard R. Despain, et al., discloses a dispenser having a flap valve which also can only operate when pressure is applied to its associated container.
Other patents of interest are U.S. Pat. Nos. 3,825,157; 4,139,124 and 2,546,709.